The instant patent provides an identification method. It is premised on the formation of antigen-antibody reactivity profiles or antibody fingerprints, that can be used to uniquely identify animals and inanimate objects. The method is particularly valuable in the rapid identification of large numbers of individuals. One embodiment of the method, termed the blocked fingerprint assay, centers on detecting allergens, autoantigens, defined as "self antigens", and environmental agents such as pathogens, chemicals, or toxins, all of which substances possess the same epitopes, or antibody binding sites. Regarding the identification of inanimate objects, the method is particularly useful to identify security documents, and the like that have legal significance, as well as valuable art work. As applied to identifying animals, particularly humans, the instant method permits identification of individuals, and thus can be expected to be applied to the fields of forensic medicine, law enforcement, and immigration.